Fill Apache Arrow arrays from ODBC data sources. This crate is build on top of the arrow and odbc-api crate and enables you to read the data of an ODBC data source as sequence of Apache Arrow record batches.
Apache Arrow defines a language-independent columnar memory format for flat and hierarchical data, organized for efficient analytic operations on modern hardware like CPUs and GPUs. The Arrow memory format also supports zero-copy reads for lightning-fast data access without serialization overhead.
ODBC (Open DataBase Connectivity) is a standard which enables you to access data from a wide variaty of data sources using SQL.
```rust use arrowodbc::{odbcapi::Environment, OdbcReader};
const CONNECTION_STRING: &str = "\ Driver={ODBC Driver 17 for SQL Server};\ Server=localhost;\ UID=SA;\ PWD=My@Test@Password1;\ ";
fn main() -> Result<(), anyhow::Error> { // Your application is fine if you spin up only one Environment. let odbc_environment = unsafe { Environment::new().unwrap() };
// Connect with database.
let connection = odbc_environment.connect_with_connection_string(CONNECTION_STRING)?;
// This SQL statement does not require any arguments.
let parameters = ();
// Execute query and create result set
let cursor = connection
.execute("SELECT * FROM MyTable", parameters)?
.expect("SELECT statement must produce a cursor");
// Each batch shall only consist of maximum 10.000 rows.
let max_batch_size = 10_000;
// Read result set as arrow batches. Infer Arrow types automatically using the meta
// information of `cursor`.
let arrow_record_batches = OdbcReader::new(cursor, max_batch_size)?;
for batch in arrow_record_batches {
// ... process batch ...
}
Ok(())
} ```
| ODBC | Arrow | | ------------------ | -------------------- | | Numeric(p <= 38) | Decimal | | Decimal(p <= 38) | Decimal | | Integer | Int32 | | SmallInt | Int16 | | Real | Float32 | | Float(p <=24) | Float32 | | Double | Float64 | | Float(p > 24) | Float64 | | Date | Date32 | | LongVarbinary | Binary | | Timestamp(p = 0) | TimestampSecond | | Timestamp(p: 1..3) | TimestampMilliSecond | | Timestamp(p: 4..6) | TimestampMicroSecond | | Timestamp(p >= 7 ) | TimestampNanoSecond | | BigInt | Int64 | | TinyInt | Int8 | | Bit | Boolean | | Varbinary | Binary | | Binary | FixedSizedBinary | | All others | Utf8 |
Appart from the afformentioned Arrow types Uint8 is also supported if specifying the Arrow schema directly.